Serum levels of their ligands CXCL13, CXCL12, and CCL19 (which may well reflect the degree of expression of these factors in peripheral tissues) have been actually shown to be inversely correlated with the frequency of blood memory CD27+ B in RA [59], suggesting that there might be a migration or redistribution of pathogenic memory B cells into different anatomic compartments, such as the inflamed synovium. The gene discussed is CXCL13; the disease is rheumatoid arthritis.